System for generating a magnetic field

ABSTRACT

Generally, a system for generating a magnetic field having a desired magnetic field strength and/or a desired magnetic field direction is provided. The system can include a plurality of magnetic segments and/or a plurality of ferromagnetic segments. Each magnetic segment can be positioned adjacent to at least one of the plurality of magnetic segments. Each ferromagnetic segment can be positioned adjacent to at least one of the plurality of magnetic segments. In various embodiments, a size, shape, positioning and/or number of magnetic segments and/or ferromagnetic segments in the system, as well as a magnetization direction of the magnetic segments can be predetermined based on, for example, predetermined parameters of the system (e.g., a desired magnetic field strength, direction and/or uniformity of the magnetic field, a desired elimination of a magnetic fringe field and/or total weight of the system) and/or based on a desired application of the system (e.g., performing a magnetic resonance imaging of at least a portion of a patient and/or performing a magnetic resonance spectroscopy of a sample).

FIELD OF THE INVENTION

Generally, the present invention relates to magnetic devices. Moreparticularly, the present invention relates to systems for generating amagnetic field.

BACKGROUND OF THE INVENTION

Generally, magnetic resonance based devices can be utilized, forexample, to image at least a portion of a patient and/or to perform amagnetic resonance spectroscopy of a sample. Typically, the magneticresonance based devices can require a generation of a substantiallyhigh, stable and/or uniform magnetic field within a measurement volumeof the device.

Some of magnetic resonance based devices can include permanent magnetsto generate a magnetic field. One difficulty in generating a magneticfield in a measurement volume using permanent magnet(s) that issufficient (e.g., that is substantially stable and/or uniform) formagnetic resonance spectroscopy and/or magnetic imaging is that magneticfields produced by the permanent magnets(s) can be non-homogeneous, thustypically resulting in a non-homogenous magnetic field within themeasurement volume.

Some current solutions for creating a homogenous and/or stable magneticfield within a measurement volume using a permanent magnet can include,for example, adding additional elements to a magnetic resonance baseddevice (e.g., coils) and/or increasing the size of the permanentmagnets. One difficulty with current solutions is that as, for example,the number of elements in the magnetic resonance based device increasesand/or the size, shape and/or weight of the permanent magnets in themagnetic resonance based device increases, the weight and/or size of thewhole device can increase, thereby increasing, for example, amanufacturing, shipment and/or installation cost.

In another example, for magnetic resonance based devices in anindustrial setting (e.g., nuclear magnetic measurement (NMR) devicesthat measure properties of fluids and/or drilling muds in oil productionfacilities), a heavy and/or large device can prevent personnel frommeasuring the fluids/muds at various locations in the processes.

SUMMARY OF THE INVENTION

There is thus provided, in accordance with some embodiments of theinvention, a magnet for generating a magnetic field having a desiredmagnetic field strength and a desired magnetic field direction, themagnet including: a plurality of magnetic segments, each magneticsegment positioned adjacent to at least one of the plurality of magneticsegments, and each magnetic segment having a magnetization direction,wherein the magnetization direction is based on the desired magneticfield strength and the desired magnetic field direction.

In some embodiments, the magnetization direction of each magneticsegment is further based on the magnetization direction of respectiveadjacent magnetic segments.

In some embodiments, each of the plurality of magnetic segments has anidentical shape.

In some embodiments, each of the plurality of magnetic segments has anidentical magnetization direction.

In some embodiments, the desired magnetic field strength and the desiredmagnetic field direction is based on an application of the magnet.

In some embodiments, each of the plurality of magnetic segments is apermanent magnet.

In some embodiments, each of the plurality of magnetic segments hasidentical size.

In some embodiments, each of the plurality of magnetic segments has ashape selected from a group consisting of: a cube, a hyper-rectangle, aparallelepiped, a sphere and a cylinder.

There is thus provided, in accordance with some embodiments of theinvention, a ferromagnetic element for generating a magnetic fieldhaving a desired magnetic field direction, the ferromagnetic elementincluding: a plurality of ferromagnetic segments, each ferromagneticsegment positioned adjacent to at least one of the plurality offerromagnetic segments, wherein the plurality of ferromagnetic form aferromagnetic element with a desired magnetic field direction.

In some embodiments, each of the plurality of ferromagnetic segments hasidentical size.

In some embodiments, each of the plurality of ferromagnetic segments hasidentical shape.

There is thus provided, in accordance with some embodiments of theinvention, a system for generating a magnetic field having a desiredmagnetic field strength and a desired magnetic field direction, thesystem including: a plurality of magnetic segments, each magneticsegment positioned adjacent to at least one of the plurality of magneticsegments, and each magnetic segment having a magnetization direction;and a plurality of ferromagnetic segments, each ferromagnetic segmentpositioned adjacent to at least one of the plurality of magneticsegments; wherein the magnetization direction is based on the desiredmagnetic field strength and the desired magnetic field direction.

In some embodiments, the magnetization direction of each magneticsegment is further based on the magnetization direction of respectiveadjacent magnetic segments.

In some embodiments, the system further includes a plurality of fluidfilled segments wherein each of the plurality of fluid filled segment ispositioned adjacent to at least one of the plurality of magneticsegments, and wherein at least one of the fluid filled segmentscomprises air.

In some embodiments, shape and size of at least one fluid filled segmentcorresponds to the shape and size of at least one of magnetic segmentsand ferromagnetic segments.

In some embodiments, at least one of the magnetic segments and theferromagnetic segments has a shape selected from a group consisting of:a cube, a hyper-rectangle, a parallelepiped, and a cylinder.

In some embodiments, the magnetization direction of at least onemagnetic segment is along an axis passing between two parallel faces ofthat magnetic segment.

In some embodiments, the magnetization direction of at least onemagnetic segment is along an axis passing between two opposite cornersof that magnetic segment.

In some embodiments, the magnetization direction of at least onemagnetic segment is along an axis passing between two opposite edges ofthat segment.

In some embodiments, the shape of at least one magnetic segmentcorresponds to the shape of at least one ferromagnetic segment.

In some embodiments, size of at least one magnetic segment correspondsto the size of at least one ferromagnetic segment.

In some embodiments, the magnetization direction of at least onemagnetic segment corresponds to a positioning of that segment within thesystem.

In some embodiments, a change in positioning of at least one magneticsegment corresponds to a change in the generated magnetic field.

In some embodiments, a change in magnetization direction of at least onemagnetic segment corresponds to a change in the generated magneticfield.

In some embodiments, the system further includes a predefined meshconfigured to arrange each of the plurality of segments into a desiredposition.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, can beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1A schematically illustrates a magnet for generating a magneticfield, according to some embodiments of the invention;

FIGS. 1B-1D schematically illustrate various magnetization directions ofa first magnetic segment, according to some embodiments of theinvention;

FIG. 2 schematically illustrates a ferromagnetic element, according tosome embodiments of the invention; and

FIGS. 3-5 schematically illustrate various configurations of a systemfor generating a magnetic field, including different number of magneticblocks and/or segments, according to some embodiments of the invention.

It will be appreciated that, for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numerals may be repeated among the figures toindicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention can be practiced without these specific details. Inother instances, well-known methods, procedures, and components have notbeen described in detail so as not to obscure the present invention.

Reference is now made to FIG. 1A, which schematically illustrates afirst magnet 100 for generating a magnetic field, according to someembodiments of the invention.

The magnet 100 (e.g., first magnet) can include a plurality of magneticsegments 110 (e.g., first magnetic segments). Each first magneticsegment 110 can be positioned adjacent to another first magnetic segment110 of the plurality of first magnetic segments 110. Each first magneticsegment 110 can have a magnetization direction 112 (e.g., indicated by adashed arrow in FIG. 1A). In some embodiments, first magnetic segments110 are permanent magnets.

The first magnet 100 can include a configuration of the first magneticsegments 110 (e.g., placement, number of magnetic segments, and/ororientation) to generate a magnetic field having a desired magneticfield strength and/or a desired magnetic field direction. In variousembodiments, the desired strength and/or direction of the magnetic fieldgenerated by the first magnet 100 is predetermined based on theapplication of the magnet. For example, the first magnet 100 can be usedin a device capable of imaging at least a portion of a patient (e.g.,the magnetic field strength in a 1 Tesla range) and/or in a devicecapable of performing a magnetic resonance spectroscopy of a sample(e.g., the magnetic field strength in a 0.1-2 Tesla range).

The magnetization direction 112 of each of the first magnetic segments110 can be predetermined based on the desired strength and/or directionof the magnetic field generated by the first magnet 100. In someembodiments, each of the first magnetic segments 110 in the first magnet100 has identical magnetization direction 112, for example as shown inFIG. 1A. In some embodiments, the magnetization direction 112 of atleast one first magnetic segment 110 is different compared to otherfirst magnetic segments 110. In some embodiments, the magnetizationdirection 112 of each of the first magnetic segments 110 in the firstmagnet 100 is predetermined based on the magnetization direction 112 ofrespective adjacent first magnetic segments 110. For example, themagnetization direction 112 of first magnetic segment 110 a can bepredetermined based on magnetization direction 112 of adjacent firstmagnetic segment 110 b and/or on magnetization direction 112 of adjacentfirst magnetic segment 110 c (e.g., as shown in FIG. 1A).

In various embodiments, each of the first magnetic segments 110 in thefirst magnet 100 has an identical shape (e.g., a cube as shown in FIG.1A) and/or at least a portion of the first magnetic segments 110 havedifferent shapes. The shape of the first magnetic segments 110 caninclude, for example, a cube, a hyper-rectangle, a parallelepiped, asphere and/or a cylinder. In various embodiments, each of the firstmagnetic segments 110 in the first magnet 100 has an identical sizeand/or shape (e.g., as shown in FIG. 1A) and/or at least a portion ofthe first magnetic segments 110 have different sizes and/or shapes. Forexample, each of the first magnetic segments 110 can have a cube shapeand/or can have an edge length ranging between 7-900 mm.

In various embodiments, the first magnet 100 can include at least onefluid filled segment 170. The fluid filled segments 170 can bepositioned adjacent to the first magnetic segments 110, for example asshown in FIG. 1A. In some embodiments, the fluid filled segments 170include air as an air gap between other first magnetic segments 110. Invarious embodiments, shape and/or size of at least one fluid filledsegment 170 corresponds to the shape and/or size of at least one firstmagnetic segment 110. In some embodiments, the structure of at least onefluid filled segment 170 has a frame to support at least one adjacentfirst magnetic segment 110.

Reference is now made to FIGS. 1B-1D, which schematically illustratevarious magnetization directions 112 of a first magnetic segment 110,according to some embodiments of the invention.

The magnetization direction 112 of the first magnetic segment 110 can bealigned along an axis passing between parallel faces of the segment, forexample faces 114 a, 114 b as shown in FigurelB. The magnetizationdirection 112 of the first magnetic segment 110 can be aligned along anaxis passing between opposite corners of the segment, for examplecorners 115 a, 115 b as shown in FIG. 1C. The magnetization direction112 of the first magnetic segment 110 can be aligned along an axispassing between opposite edges of the segment, for example edges 116 a,116 b as shown in FIG. 1D.

Reference is now made to FIG. 2, which schematically illustrates aferromagnetic element 200, according to some embodiments of theinvention.

The ferromagnetic element 200 (e.g., first ferromagnetic element), forexample a pole piece for an MRI device, can include a plurality offerromagnetic segments 210 (e.g., first ferromagnetic segments). Each ofthe first ferromagnetic segments 210 can be positioned adjacent to theat least one other first ferromagnetic segment 210.

In various embodiments, each of the first ferromagnetic segments 210 inthe first ferromagnetic element 200 has an identical shape (e.g., a cubeas shown in FIG. 2) and/or at least a portion of the first ferromagneticsegments 210 have different shapes. In various embodiments, each of thefirst ferromagnetic segments 210 in first ferromagnetic element 200 hasan identical size (e.g., as shown in FIG. 2) and/or at least a portionof the first ferromagnetic segments 210 have different sizes. In someembodiments, the first ferromagnetic segments 210 form the firstferromagnetic element 200 with a desired magnetic field direction.

The first ferromagnetic element 200 can include at least one fluidfilled segment 270. The fluid filled segment 270 can be positionedadjacent to and/or between the ferromagnetic segments 210, for exampleas shown in FIG. 2. In some embodiments, the fluid filled segments 270include air as an air gap between other ferromagnetic segments 210. Invarious embodiments, shape and/or size of at least one fluid filledsegment 270 corresponds to the shape and/or size of least oneferromagnetic segment 210. In some embodiments, the structure of atleast one fluid filled segment 270 has a frame to support at least oneadjacent first ferromagnetic segment 210.

Reference is now made to FIGS. 3-5, which schematically illustratevarious configurations of a system for generating a magnetic field,including different number of magnetic blocks and/or segments, accordingto some embodiments of the invention.

FIG. 3 illustrates a system 300 for generating a magnetic field that caninclude, for example, one first magnetic block 310, one second magneticblock 320 and/or one third magnetic block 330. It is appreciated thatFIG. 3 schematically illustrates a portion (e.g., one-eighth) of theentire system 300. In some embodiments, at least one of the firstmagnetic block 310, second magnetic block 320 and/or third magneticblock 330 is a permanent magnet. Each of the first magnetic block 310,second magnetic block 320 and/or third magnetic block 330 can bepositioned adjacent to at least one of the other magnetic blocks. Forexample, the first magnetic block 310 can be positioned adjacent to thesecond and/or third magnetic blocks 320, 330, respectively (e.g., asshown in FIG. 3). The first magnetic block 310, second magnetic block320 and/or third magnetic block 330 can generate a magnetic field with adesired strength and/or direction within the system 300. In variousembodiments, each of the first magnetic block 310, second magnetic block320 and/or third magnetic block 330 has a shape selected from a groupconsisting of: a cube, a hyper-rectangle, a parallelepiped, and/or acylinder. For example, each of the first magnetic block 310, secondmagnetic block 320 and/or third magnetic block 330 can have ahyper-rectangle shape and/or a length of 180 mm and/or a width of 90 mm(e.g., as shown in FIG. 3).

The system 300 can include at least one ferromagnetic block 360 that canbe positioned adjacent to at least one of the first magnetic block 310,second magnetic block 320 and/or third magnetic block 330.

Each of the first magnetic block 310, second magnetic block 320, and/orthird magnetic block 330 can have a predetermined magnetizationdirection. For example, the magnetization direction of the firstmagnetic block 310 can be aligned along the Z axis, the magnetizationdirection of the second magnetic block 320 can be aligned along the Xaxis and/or the magnetization direction of the third magnetic block 330can be aligned along the Y axis (e.g., as indicated by a dashed arrow inFIG. 3). As may be apparent to one of ordinary skill in the art, whileFIG. 3 illustrates the magnetization directions of the first magneticblock 310, second magnetic block 320 and third magnetic block 330 beingparallel to Z, X, Y axes, respectively, each of the first magnetic block310, second magnetic block 320 and third magnetic block 330 can have amagnetization in various directions.

The system 300 can include a shell 380. The shell 380 can at leastpartly surround the first magnetic block 310, second magnetic block 320,third magnetic block 330 and/or the at least one ferromagnetic block360. The shell 380 can include a metal alloy and/or can substantiallyreduce a magnetic fringe filed outside the shell. In variousembodiments, the first magnetic block 310, second magnetic block 320,third magnetic block 330 and/or the ferromagnetic block 360 are arrangedwithin the shell 380 to form a measurement volume 390. The shell 380 canalso include an opening (not shown) to provide an access to themeasurement volume 390. In some embodiments, the measurement volume 390includes air.

FIG. 4 illustrates a system 400 for generating a magnetic field that caninclude a plurality of magnetic segments, for example, second magneticsegments 412, third magnetic segments 422 and/or fourth magneticsegments 432. It is appreciated that FIG. 4 schematically illustrates aportion (e.g., one-eighth) of the entire system 400. In someembodiments, at least a portion of the second magnetic segments 412,third magnetic segments 422, and fourth magnetic segments 432 arepermanent magnets. The second magnetic segments 412, third magneticsegments 422 and/or fourth magnetic segments 432 can generate a magneticfield with a desired strength and/or direction within the system 400. Invarious embodiments, the second magnetic segments 412 form a secondmagnet 410, the third magnetic segments 422 form a third magnet 420and/or the fourth magnetic segments 432 form a fourth magnet 430. Atleast one of the second magnet 410, the third magnet 420, and/or thefourth magnet 430 can be identical to the first magnet 100. At least oneof the second magnetic segments 412, third magnetic segments 422, and/orfourth magnetic segments 432 can be identical to the first magneticsegments 110 as described above with respect to FIG. 1A.

Each of the second magnetic segments 412, third magnetic segments 422,and/or fourth magnetic segments 432 can be positioned adjacent to the atleast one of the plurality of the magnetic segments. For example, eachof the second magnetic segments 412 can be positioned adjacent to atleast one second magnetic segment 412 and/or at least one secondmagnetic segments 412 can be positioned adjacent to the third magneticsegments 422 (e.g., as shown in FIG. 4).

The system 400 can include a plurality of second ferromagnetic segments462. Each second ferromagnetic segment 462 can be positioned adjacent toat least one of the plurality of the second ferromagnetic segments 462and/or adjacent to the at least one of the second magnetic segments 412,third magnetic segments 422, and/or fourth magnetic segments 432. Thesecond ferromagnetic segments 462 can form at least one secondferromagnetic element 460 with a desired magnetic field and/or a desiredstrength direction. The at least one second ferromagnetic element 460can be identical to the first ferromagnetic element 200 and/or each ofthe second ferromagnetic segments 462 can be identical to at least onefirst ferromagnetic segment 210, as described above with respect to FIG.2. The at least one second ferromagnetic element 460 can be positionedadjacent to at least one of the second magnets 410, third magnet 420and/or fourth magnet 430 of the system 400.

The system 400 can include a plurality of fluid filled segments 470. Thefluid filled segments 470 can be positioned adjacent to at least onesecond magnetic segment 412, third magnetic segment 422, and/or fourthmagnetic segment 432 (e.g., as shown in FIG. 4) and/or adjacent to atleast one of the second ferromagnetic segments 462. In some embodiments,the fluid filled segments 470 include air. In some embodiments, thestructure of at least one fluid filled segment 470 has a frame tosupport at least one of adjacent second magnetics segment 412, thirdmagnetic segments 422, fourth magnetic segments 432 and/or secondferromagnetic segment 462.

In various embodiments, the shape and/or size of at least one fluidfilled segment 470 corresponds to the shape and/or size of at least onesecond magnetic segment 412, third magnetic segment 422, fourth magneticsegment 332 and/or second ferromagnetic segment 362. In variousembodiments, at least one second magnetic segments 312, third magneticsegment 322, fourth magnetic segment 432 and/or second ferromagneticsegment 462 has a shape selected from a group consisting of: a cube, ahyper-rectangle, a parallelepiped, and/or a cylinder. In variousembodiments, the shape and/or the size of at least one second magneticsegment 412, third magnetic segment 422, and/or fourth magnetic segment432 corresponds to the shape and/or the size of at least one secondferromagnetic segment 462. For example, each of the second magneticsegments 412, third magnetic segments 422, third magnetic segments 432and/or second ferromagnetic segments 462 can have a cubic shape and/oran edge length of 30 mm (e.g., as shown in FIG. 4). The system 400 caninclude a shell 480. The shell 480 can at least partly surround thesecond magnetic segments 412, third magnetic segment 422, fourthmagnetic segment 432, second ferromagnetic segments 462 and/or fluidfilled segments 470. In some embodiments, the shell 480 is identical tothe shell 380 as described above with respect to FIG. 3. The shell 480can include a metal alloy and/or can substantially reduce a magneticfringe filed outside the shell. In various embodiments, the secondmagnetic segments 412, third magnetic segment 422, fourth magneticsegment 332 the ferromagnetic segments 462 and/or the fluid filledsegments 470 are arranged within the shell 480 to form a measurementvolume 490. The shell 480 can also include an opening (not shown) toprovide an access to the measurement volume 490. In some embodiments,the measurement volume 490 includes air. In some embodiments, themeasurement volume 490 is identical to the measurement volume 390 asdescribed above with respect to FIG. 3.

Each of the second magnetic segments 412, third magnetic segments 422,and/or fourth magnetic segments 432 can have a predeterminedmagnetization direction. For example, the magnetization direction of thesecond magnetic segments 412 can be aligned along the Z axis, themagnetization direction of the third magnetic segments 422 can bealigned along the X axis and/or the magnetization direction of thefourth magnetic segments 432 can be aligned along the Y axis (e.g., asindicated by a dashed arrow in FIG. 4).

As may be apparent to one of ordinary skill in the art, while FIG. 4illustrates the magnetization directions of the second magnetic segments412, third magnetic segments 422, and fourth magnetic segments 432 beingparallel to Z, X, Y axes, respectively, each of the second magneticsegments 412, third magnetic segments 422, and fourth magnetic segments432 can have a magnetization in various directions. For example, themagnetization direction of at least a portion of the second magneticsegments 412, third magnetic segments 422, and/or fourth magneticsegments 432 can be along an axis passing between two parallel faces ofthat magnetic segment (e.g., as shown in FIGS. 1A, 1B, and 3), along anaxis passing between two opposite corners of that magnetic segment(e.g., as shown in FIG. 1C) and/or along an axis passing between twoopposite edges of that magnetic segment (e.g., as shown in FIG. 1D).

In various embodiments, the magnetization direction of each of thesecond magnetic segments 412, third magnetic segments 422, and/or fourthmagnetic segments 432 can be based on the desired strength and/ordirection of the magnetic field generated by the system 400. Themagnetization direction of each of the second magnetic segments 412,third magnetic segments 422, and/or fourth magnetic segments 432 canalso be based on the magnetization direction of respective adjacentmagnetic segments. For example, the magnetization direction of secondmagnetic segment 412 a can be based on the magnetization direction ofadjacent second magnetic segments 412 and/or based on the magnetizationdirection of adjacent third and/or fourth magnetic segments 422 a, 432a, respectively (e.g., as shown in FIG. 4).

The magnetization direction of each of the second magnetic segments 412,third magnetic segments 422, and/or fourth magnetic segments 432 cancorrespond to a positioning of that segment within the system 400. Forexample, a position of second magnetic segment 412 a in the system 400can be predetermined and/or the magnetization direction of the secondmagnetic segment 412 a can be thereby predetermined based on thepredetermined position of the second magnetic segment 412 a.

In various embodiments, a change in positioning and/or in themagnetization direction of the at least one of the second magneticsegments 412, third magnetic segments 422, and/or fourth magneticsegments 432 can correspond to a change in the magnetic field generatedby the system 400. For example, a change in the predetermined positionand/or the predetermined magnetization direction of the second magneticsegment 412 a can change the direction and/or the strength of themagnetic field generated by the system 400.

The system 400 can include a predefined mesh. The mesh can be configuredto arrange each of the second magnetic segments 412, third magneticsegments 422, fourth magnetic segments 432 and/or second ferromagneticsegments 462 into a predetermined position. The mesh can be made of anon-magnetic and/or a non-paramagnetic material, for example, titanium.

FIG. 5 illustrates a system 500 for generating a magnetic field that caninclude a plurality of magnetic segments, for example fifth magneticsegments 512, sixth magnetic segments 522 and/or seventh magneticsegments 532. It is appreciated that FIG. 5 schematically illustrates aportion (e.g., one-eighth) of the entire system 500. In someembodiments, at least a portion of fifth magnetic segments 512, sixthmagnetic segments 522, and seventh magnetic segments 532 are permanentmagnets. The fifth magnetic segments 512, sixth magnetic segments 522and/or seventh magnetic segments 532 can generate a magnetic field witha desired strength and/or direction within the system 500.

In various embodiments, the fifth magnetic segments 512 form a fifthmagnet 510, the sixth magnetic segments 522 form a sixth magnet 520and/or the seventh magnetic segments 532 form a seventh magnet 530. Atleast one of the fifth magnet 510, sixth magnet 520, and/or seventhmagnet 430 can be identical to the first magnet 100 (e.g., as describedabove with respect to FIG. 1A), second magnet 410, third magnet 420and/or fourth magnet 440 (e.g., as described above with respect to FIG.4). At least one of the fifth magnetic segments 512, sixth magneticsegments 522 and/or seventh magnetic segments 532 can be identical tothe first magnetic segments 110 (e.g., as described above with respectto FIG. 1A), second magnetic segments 412, third magnetic segments 422and/or fourth magnetic segments 432 (e.g., as described above withrespect to FIG. 4). Each of the fifth magnetic segments 512, sixthmagnetic segments 522 and/or seventh magnetic segments 532 can bepositioned adjacent to the at least one of the plurality of the magneticsegments (e.g., as described above with respect to FIG. 4).

The system 500 can include a plurality of third ferromagnetic segments562 that can form at least one third ferromagnetic element 560 with adesired magnetic field and/or a desired strength direction. The at leastone second ferromagnetic element 560 can be identical to the firstferromagnetic element 200 (e.g., as described above with respect to FIG.2) and/or second ferromagnetic element 460 (e.g., as described abovewith respect to FIG. 4). Each of the third ferromagnetic segments 562can be identical to at least one first ferromagnetic segment 210 (e.g.,as described above with respect to FIG. 2) and/or the secondferromagnetic segments 462 (e.g., as described above with respect toFIG. 4). The at least one third ferromagnetic element 560 can bepositioned adjacent at least one of the fifth magnets 510, sixth magnet520, and/or seventh magnet 530 of the system 500 (e.g., as describedabove with respect to FIG. 4).

The system 500 can include a plurality of fluid filled segments 570 thatcan include air. The fluid filled segments 570 can be positionedadjacent to at least one fifth magnetic segment 512, sixth magneticsegment 522, and/or seventh magnetic segment 532 and/or adjacent to atleast one of the third ferromagnetic segments 562 (e.g., as shown inFIG. 5).

The system 500 can include a shell 580 and/or a measurement volume 590.In various embodiments, the shell 580 is identical to the shell 380, asdescribed above with respect to FIG. 3, and/or to the shell 480, asdescribed above with respect to FIG. 4. In various embodiments, themeasurement volume 590 is identical to the measurement volume 390, asdescribed above with respect to FIG. 3, and/or to the measurement volume490, as described above with respect to FIG. 4.

In various embodiments, each of the fifth magnetic segments 512, sixthmagnetic segments 522, seventh magnetic segments 532 and/or thirdferromagnetic segments 562 has a shape selected from a group consistingof: a cube, a hyper-rectangle, a parallelepiped, and a cylinder. Forexample, each of the fifth magnetic segments 512, sixth magneticsegments 522, seventh magnetic segments 532 and/or third ferromagneticsegments 562 can have a cubic shape and/or the edge length of 7.5 mm(e.g., as shown in FIG. 5).

In various embodiments, the position, shape and/or a size of each of thefifth magnetic segments 512, sixth magnetic segments 522, seventhmagnetic segments 532, third ferromagnetic segments 562 and/or fluidfilled segments 570 is predetermined based on, for example, the strengthand/or direction of the magnetic field generated by the system 500(e.g., as described above with respect to FIG. 4).

In various embodiments, a magnetization direction of each of the fifthmagnetic segments 512, sixth magnetic segments 522 and/or seventhmagnetic segments 532 is predetermined based on, for example, a strengthand/or direction of a magnetic field generated by the system 500 (e.g.,as described above with respect to FIG. 4). For example, themagnetization direction of the fifth magnetic segments 512 can bealigned along the Z axis, the magnetization direction of the sixthmagnetic segments 522 can be aligned along the X axis and/or themagnetization direction of the fourth magnetic segments 532 can bealigned along the Y axis (e.g., as shown in FIG. 5).

Reference is now made back to FIGS. 3-5. In embodiments, a size, shape,positioning and/or number of magnetic segments and/or blocks,ferromagnetic segments and/or blocks and/or fluid filled segments in asystem for generating a magnetic field, as well as a magnetizationdirection of the magnetic segments and/or blocks is predetermined basedon, for example, predetermined parameters of the system and/or based ona desired application of the system. The desired application of thesystem can include, for example, performing a magnetic resonance imagingof at least a portion of a patient and/or performing a magneticresonance spectroscopy of a sample. The predetermined requirements ofthe system can include, for example, a desired magnetic field strength,direction and/or uniformity of the magnetic field, a desired eliminationof a magnetic fringe field and/or total weight of the system.

In various embodiments, some magnetic segments and/or blocks can have,for example, more uniform magnetic field as compared to other magneticsegments and/or blocks. In various embodiments, some magnetic segmentsand/or blocks can have smaller dimensions compared to other magneticsegments and/or blocks. Accordingly, assembling a system for generatinga magnetic field using a plurality of small magnetic segments and/orblocks can, for example, increase a strength of the generated magneticfield, improve a shimming to increase a uniformity of the generatedmagnetic field and/or substantially reduce a generated magnetic fringefield while, for example, reducing a total mass of the magnetic materialbeing used, as compared to a system being assembled using, for example,a smaller number of magnetic segments and/or blocks having largerdimensions.

For example, system 400 that can include a plurality of cubic secondmagnetic segments 412, third magnetic segments 422 and/or fourthmagnetic segments 432 having the edge length of 30 mm (e.g., as shown inFIG. 4) can generate a magnetic field (e.g., the magnetic field that ismeasured at a center of the measurement volume) that is stronger by 6.2%as compared to a magnetic field generated by the system 300 that caninclude the hyper-rectangular first magnetic blocks 310, second magneticblocks 320 and/or third magnetic blocks 330 having the length of 180 mmand width of 90 mm (e.g., as shown in FIG. 3). Similarly, reducing theedge length of the cubic magnetic segments (e.g., the cubic secondmagnetic segments 412, third magnetic segments 422 and/or fourthmagnetic segments 432) to, for example, 15 mm (not shown) and 7.5 mm(e.g., as in the system 500 as shown in FIG. 5) can increase thestrength of the generated magnetic field by 7.1% and 7.4%, respectively,as compared to the system 300.

In another example, a uniformity of magnetic field (e.g., determined by{max(B)−min(B)}/B₀, where B is the magnetic field in a field of view ina radius of 30 mm with respect to the center of the measurement volumeand B₀ is the magnetic field in the center of the measurement volumethereof) generated by the system 400 that can include a plurality ofcubic second magnetic segments 412, third magnetic segments 422 and/orfourth magnetic segments 432 having the edge length of 30 mm (e.g., asshown in FIG. 4) can be improved by 14% as compared to a uniformity ofmagnetic field generated by the system 300 that can includehyper-rectangular first hyper-rectangular magnetic block 310, secondmagnetic block 320 and/or third magnetic block 330 having the length of180 mm and width of 90 mm (e.g., as shown in FIG. 3). Similarly,reducing the edge length of the cubic magnetic segments (e.g., the cubicsecond magnetic segments 412, third magnetic segments 422 and/or fourthmagnetic segments 432) to, for example, 15 mm (not shown), may improvethe uniformity of magnetic field by 24% as compared to the system 300.

In another example, a magnetic fringe field generated by the system 400(e.g., the magnetic field measured at a predetermined distance of 250 mmfrom the center of the measurement volume) that can include a pluralityof cubic second magnetic segments 412, third magnetic segments 422and/or fourth magnetic segments 432 having the edge length of 30 mm(e.g., as shown in FIG. 4) can be smaller by 36.2% as compared to amagnetic fringe field generated by the system 300 that can includehyper-rectangular first hyper-rectangular magnetic block 310, secondmagnetic block 320 and/or third magnetic block 330 having the length of180 mm and width of 90 mm (e.g., as shown in FIG. 3). Assembling asystem for generating a magnetic field using a plurality of magneticsegments (e.g., system 400, 500 as shown in FIGS. 4, 5, respectively)can allow forming magnets (e.g., second magnet 410, third magnet 420and/or fourth magnet 430 as shown in FIG. 4) that can include variousshapes, which are not limited to, for example, a cube, ahyper-rectangle, a parallelepiped, and a cylinder. In embodiments,magnetic segments, ferromagnetic segments and/or the fluid filledsegments in a system for generating a magnetic field (e.g., the systems300, 400, 500 as shown in FIGS. 3, 4, 5, respectively) can be scaled insize to generate the magnetic field having a desired strength and/or toprovide desired dimensions of a measurement volume (e.g., themeasurement volume 390, 490, 590 as shown in FIGS. 3, 4, 5,respectively) based on, for example, a desired application of the system(e.g., performing a magnetic resonance imaging of at least a portion ofa patient and/or performing a magnetic resonance spectroscopy of asample).

Unless explicitly stated, the method embodiments described herein arenot constrained to a particular order in time or chronological sequence.Additionally, some of the described method elements can be skipped, orthey can be repeated, during a sequence of operations of a method.

Various embodiments have been presented. Each of these embodiments canof course include features from other embodiments presented, andembodiments not specifically described can include various featuresdescribed herein.

1. A magnet for generating a magnetic field having a desired magneticfield strength and a desired magnetic field direction, the magnetcomprising: a plurality of magnetic segments, each magnetic segmentpositioned adjacent to at least one of the plurality of magneticsegments, and each magnetic segment having a magnetization direction,wherein the magnetization direction is based on the desired magneticfield strength and the desired magnetic field direction.
 2. The magnetof claim 1, wherein the magnetization direction of each magnetic segmentis further based on the magnetization direction of respective adjacentmagnetic segments.
 3. The magnet of claim 1, wherein each of theplurality of magnetic segments has an identical shape.
 4. The magnet ofclaim 1, wherein each of the plurality of magnetic segments has anidentical magnetization direction.
 5. The magnet of claim 1, wherein thedesired magnetic field strength and the desired magnetic field directionis based on an application of the magnet.
 6. The magnet of claim 1,wherein each of the plurality of magnetic segments is a permanentmagnet.
 7. The magnet of claim 1, wherein each of the plurality ofmagnetic segments has identical size.
 8. The magnet of claim 1, whereineach of the plurality of magnetic segments has a shape selected from agroup consisting of: a cube, a hyper-rectangle, a parallelepiped, asphere and a cylinder.
 9. A ferromagnetic element for generating amagnetic field having a desired magnetic field direction, theferromagnetic element comprising: a plurality of ferromagnetic segments,each ferromagnetic segment positioned adjacent to at least one of theplurality of ferromagnetic segments, wherein the plurality offerromagnetic form a ferromagnetic element with a desired magnetic fielddirection.
 10. The ferromagnetic element of claim 9, wherein each of theplurality of ferromagnetic segments has identical size.
 11. Theferromagnetic element of claim 9, wherein each of the plurality offerromagnetic segments has identical shape.
 12. A system for generatinga magnetic field having a desired magnetic field strength and a desiredmagnetic field direction, the system comprising: a plurality of magneticsegments, each magnetic segment positioned adjacent to at least one ofthe plurality of magnetic segments, and each magnetic segment having amagnetization direction; and a plurality of ferromagnetic segments, eachferromagnetic segment positioned adjacent to at least one of theplurality of magnetic segments; wherein the magnetization direction isbased on the desired magnetic field strength and the desired magneticfield direction.
 13. The system of claim 12, wherein the magnetizationdirection of each magnetic segment is further based on the magnetizationdirection of respective adjacent magnetic segments.
 14. The system ofclaim 12, further comprising a plurality of fluid filled segmentswherein each of the plurality of fluid filled segment is positionedadjacent to at least one of the plurality of magnetic segments, andwherein at least one of the fluid filled segments comprises air.
 15. Thesystem of claim 14, wherein shape and size of at least one fluid filledsegment corresponds to the shape and size of at least one of magneticsegments and ferromagnetic segments.
 16. The system of claim 12, whereinat least one of the magnetic segments and the ferromagnetic segments hasa shape selected from a group consisting of: a cube, a hyper-rectangle,a parallelepiped, and a cylinder.
 17. The system of claim 12, whereinthe magnetization direction of at least one magnetic segment is along anaxis passing between two parallel faces of that magnetic segment. 18.The system of claim 12, wherein the magnetization direction of at leastone magnetic segment is along an axis passing between two oppositecorners of that magnetic segment.
 19. The system of claim 12, whereinthe magnetization direction of at least one magnetic segment is along anaxis passing between two opposite edges of that segment.
 20. The systemof claim 12, wherein the shape of at least one magnetic segmentcorresponds to the shape of at least one ferromagnetic segment.
 21. Thesystem of claim 12, wherein size of at least one magnetic segmentcorresponds to the size of at least one ferromagnetic segment.
 22. Thesystem of claim 12, wherein the magnetization direction of at least onemagnetic segment corresponds to a positioning of that segment within thesystem.
 23. The system of claim 12, wherein a change in positioning ofat least one magnetic segment corresponds to a change in the generatedmagnetic field.
 24. The system of claim 12, wherein a change inmagnetization direction of at least one magnetic segment corresponds toa change in the generated magnetic field.
 25. The system of claim 12,further comprising a predefined mesh configured to arrange each of theplurality of segments into a desired position.